Contemporary standards of personal hygiene require regular cleaning of the hair to maintain a presentable appearance. Modern shampoo compositions effectively clean the hair, by removing excess soil and sebum, and can also include additional ingredients such as conditioners. Exemplary conditioners and conditioning shampoo formulations are disclosed by Roberts et al., U.S. Pat. No. 3,590,122; Bolich et al., U.S. Pat. No. 3,808,329; Angvillo et al., U.S. Pat. No. 3,816,616; Hofman et al., U.S. Pat. No. 4,272,515; and Dixon et al., U.S. Pat. No. 4,701,322.
Shampoo and shampoo/conditioner compositions have hitherto been formulated for packaging and dispensing from conventional containers, such as plastic bottles, tubes, etc. With the development of the soft gelatin capsule, or softgel, an alternative form of dispensing and applying shampoos has become available. Encapsulation of a shampoo composition in a softgel offers numerous advantages. For example, no additional packaging would be needed for the shampoo-filled softgels. The shampoo could be prepared in pre-measured quantities sufficient for cleaning the hair, thus minimizing shampoo waste. The shampoo could be dispensed from the softgel while the user is showering, typically by squeezing or breaking the softgel, and the empty softgel could then be disposed of simply and easily, for example by dropping it to the floor of the shower to dissolve.
For practicable encapsulation within a softgel, however, a shampoo composition must be compatible with the softgel. In particular, the shampoo composition must be formulated such that it can be stably encapsulated in the softgel shell without dissolving the softgel. The shampoo composition should be formulated such that it is stable in encapsulated form for extended periods of time at room temperature.
A need exists for a shampoo/conditioner composition that is compatible with a softgel shell and can be encapsulated stably in a softgel.